Solution treatment method for additive manufactured gh3625 alloy

Abstract

This invention relates to the field of additive manufacturing technology, and in particular to a solution treatment method for additive manufacturing of GH3625 alloy. The solution treatment method for additive manufacturing of GH3625 alloy includes the following steps: holding the additive-manufactured GH3625 alloy part at 650–750°C, then raising the temperature to 950–1050°C and holding it thereafter, followed by furnace cooling. Based on the unique microstructure of additive-manufactured GH3625 alloy, this invention specifically designs a solution treatment regime suitable for additive manufacturing of GH3625 alloy, which can significantly reduce the risk of deformation and cracking of additive-manufactured GH3625 alloy parts during the solution treatment stage, and significantly improve the overall mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to a solution treatment method for additive manufacturing of GH3625 alloy. Background Technology

[0002] GH3625 alloy is a solid solution strengthened nickel-based wrought superalloy with excellent tensile and fatigue properties. It maintains good mechanical properties from low temperatures up to 980℃ and exhibits excellent corrosion resistance, making it widely applicable in the manufacture of key components for aerospace engines and chemical equipment. With the development of aerospace and other fields, the structural complexity of key components is increasing. Traditional processing methods such as casting and forging present challenges due to high design difficulty and long processing cycles, hindering the development of these fields.

[0003] Compared to traditional manufacturing methods, additive manufacturing offers advantages such as rapid machining of complex parts, shorter product development cycles, and improved material utilization, gradually becoming one of the important methods for manufacturing key aerospace components. However, due to the rapid cooling characteristics of additive manufacturing, the microstructure of additively manufactured GH3625 alloy in its deposited state differs significantly from that of cast and forged parts. Conventional heat treatment processes cannot meet the microstructure and mechanical property requirements of additively manufactured GH3625 alloy.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a solution treatment method for additive manufacturing of GH3625 alloy, which can reduce the risk of deformation and cracking, and improve the mechanical properties of additively manufactured GH3625 alloy and reduce the difference in mechanical properties between the transverse and longitudinal directions.

[0006] To achieve the above-mentioned objectives of this invention, this invention provides a solution treatment method for additive manufacturing of GH3625 alloy, comprising the following steps:

[0007] The additively manufactured GH3625 alloy parts are heat-treated at 650-750℃, then heated to 950-1050℃ and heat-treated again, and then cooled in the furnace.

[0008] In a specific embodiment of the present invention, the heat treatment time at 950-1050°C is 60-120 minutes.

[0009] In a specific embodiment of the present invention, the heat treatment time at 650-750°C is 240-360 minutes.

[0010] In a specific embodiment of the present invention, the heating rate during the heat treatment to 950-1050°C is 5°C / min.

[0011] In a specific embodiment of the present invention, during the solution treatment, the additively manufactured GH3625 alloy part is loaded into the furnace at room temperature. Further, the temperature is increased from room temperature to 650–750°C at a heating rate of 5°C / min.

[0012] In a specific embodiment of the present invention, the additively manufactured GH3625 alloy part has a thin-walled structure. Further, the wall thickness of the thin-walled structure is 0.5–1.0 mm.

[0013] In a specific embodiment of the present invention, the method for preparing the additive manufacturing GH3625 alloy part includes: 3D printing GH3625 alloy powder under vacuum or protective atmosphere; the power of the 3D printing is 220-340W, and the scanning speed of the 3D printing is 800-1100mm / s.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] Based on the microstructure of additively manufactured GH3625 alloy, this invention specifically designs a solution treatment process suitable for additively manufactured GH3625 alloy. This process can significantly reduce the risk of deformation and cracking of additively manufactured GH3625 alloy parts during the solution treatment stage, uniformly refine the microstructure after solution treatment, and significantly improve the overall mechanical properties. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 A comparison diagram of the tensile strength of transverse printed specimens provided by the present invention after solution treatment according to the embodiments and comparative examples;

[0018] Figure 2 Comparison of yield strength of longitudinally printed specimens after solution treatment according to the embodiments and comparative examples provided by the present invention. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0020] According to the high-temperature alloy handbook, the solution heat treatment regime for GH3625 alloy castings or forgings is 1090–1200℃ / AC or WQ. Due to the rapid cooling forming characteristics of additive manufacturing, the microstructure of additively manufactured GH3625 in the deposited state differs significantly from that of castings and forgings, exhibiting strong anisotropy and high residual stress. Conventional heat treatment not only carries a high risk of deformation and cracking in the alloy parts, but the corresponding physicochemical test results also fail to meet the performance requirements of current aerospace engines for key component materials. Furthermore, for additively manufactured GH3625 alloy parts, especially large thin-walled parts, existing solution heat treatment regimes are difficult to control in terms of shape, and there are significant differences in transverse and longitudinal mechanical properties. Based on this, this invention designs a solution treatment regime suitable for additively manufactured GH3625 alloy parts, based on the microstructure, to reduce the risk of deformation and cracking and significantly improve its comprehensive mechanical properties.

[0021] This invention provides a solution treatment method for additive manufacturing of GH3625 alloy, comprising the following steps:

[0022] The additively manufactured GH3625 alloy parts are heat-treated at 650-750℃, then heated to 950-1050℃ and heat-treated again, and then cooled in the furnace.

[0023] In the solution treatment of this invention, the additively manufactured GH3625 alloy part is first held at 650–750°C to eliminate or reduce residual stress in the alloy part. This avoids cracking and deformation during subsequent solution treatment and, combined with a relatively low solution temperature of 950–1050°C, achieves a uniform and fine grain size. Simultaneously, after the holding treatment, furnace cooling is used to allow uniform and dispersed carbides to precipitate from the solution, improving mechanical properties.

[0024] In different embodiments, the GH3625 alloy parts may first be heat-treated at a temperature of 650°C, 700°C, 750°C or any combination thereof, and then heat-treated at a temperature of 950°C, 980°C, 1000°C, 1020°C, 1050°C or any combination thereof.

[0025] In a specific embodiment of the present invention, the heat treatment time at 950-1050°C is 60-120 minutes.

[0026] The holding time at 950–1050°C is adjusted within the above range to ensure uniformity of microstructure and composition while avoiding coarse grains. For example, in different embodiments, the holding time at 950–1050°C can be 60 min, 90 min, 120 min, or any combination thereof.

[0027] In a specific embodiment of the present invention, the heat treatment time at 650-750°C is 240-360 minutes.

[0028] The holding time at 650–750°C is adjusted within the aforementioned range to fully eliminate or reduce residual stress in the alloy parts and improve deformation and cracking issues. Further heating to the solution temperature, combined with furnace cooling, further controls deformation and cracking during solution treatment, and improves mechanical properties and anisotropy. In different embodiments, the holding time at 650–750°C can be 240 min, 300 min, 360 min, or any combination thereof.

[0029] In a specific embodiment of the present invention, during the heat treatment at 950-1050°C, the heating rate is 5°C / min.

[0030] A suitable heating rate should be adopted to avoid excessive stress inside the alloy part during the heating process, which could cause deformation or cracks, while ensuring that the alloy grain size is small, thus improving strength and toughness. The heating rate should be 5℃ / min during the heating stage from 650–750℃ to 950–1050℃.

[0031] In a specific embodiment of the present invention, the temperature is increased from room temperature to 650-750°C at a heating rate of 5°C / min.

[0032] In a specific embodiment of the present invention, during the solution treatment, the additively manufactured GH3625 alloy parts are loaded into the furnace at room temperature.

[0033] In a specific embodiment of the present invention, the additively manufactured GH3625 alloy part has a thin-walled structure. Further, the wall thickness of the thin-walled structure is 0.5–1.0 mm.

[0034] Due to the rapid cooling characteristics of additively manufactured GH3625 alloy parts, deformation and cracking are prone to occur during the solution treatment stage. This is especially true for large, thin-walled parts with thin-walled structures, where shape control is more difficult and the differences in mechanical properties between the transverse and longitudinal directions are greater. This invention, by employing an appropriate heating process, an appropriate solution temperature, and a specific cooling method, not only effectively controls the deformation and cracking problems of additively manufactured GH3625 alloy parts, ensuring that large, thin-walled parts with thin-walled structures do not deform and crack during the solution treatment of this invention, but also improves their mechanical properties.

[0035] In a specific embodiment of the present invention, the method for preparing additively manufactured GH3625 alloy parts includes: 3D printing GH3625 alloy powder under vacuum or protective atmosphere; the power of 3D printing is 220-340W, and the scanning speed of 3D printing is 800-1100mm / s.

[0036] The GH3625 alloy powder of the present invention can be prepared by conventional methods, such as vacuum melting and gas atomization, but is not limited thereto. The particle size of the alloy powder used for 3D printing can be 15–53 μm.

[0037] The GH3625 alloy powder of the present invention comprises the following components by mass percentage: Cr 20%–23%, Fe ≤5%, C ≤0.1%, Mn ≤0.5%, Si ≤0.5%, Mo 8%–10.0%, Cu ≤0.07%, Co ≤1%, Al ≤0.4%, Ti ≤0.4%, Nb 3.15%–4.15%, P ≤0.015%, S ≤0.015%, with the balance being Ni.

[0038] The preparation method of additive manufacturing GH3625 alloy parts used in the following embodiments of the present invention is as follows, but is not limited thereto.

[0039] The method for preparing GH3625 alloy parts by additive manufacturing includes: preparing 3D printing samples using GH3625 alloy powder with a particle size of 15-53μm through SLM process. The 3D printing process parameters are: 3D printing power of 300W, 3D printing scanning speed of 1000mm / s, 3D printing spot diameter of 0.09mm, 3D printing scanning spacing of 0.11mm, and 3D printing powder layer thickness of 0.06mm.

[0040] In practice, to verify the performance of horizontal and vertical printing, horizontal and vertical printing samples can be prepared according to the above 3D printing process parameters.

[0041] Example 1

[0042] This embodiment provides a solution treatment method for additive manufacturing of GH3625 alloy, including the following steps: loading the additive manufacturing GH3625 alloy sample into a furnace at room temperature, then heating it to 750℃ at a heating rate of 5℃ / min and holding it at that temperature for 300min, then heating it to 1000℃ at a heating rate of 5℃ / min and holding it at that temperature for 60min, and then cooling it in the furnace.

[0043] Example 2

[0044] This embodiment provides a solution treatment method for additive manufacturing of GH3625 alloy, including the following steps: loading the additive manufacturing GH3625 alloy sample into a furnace at room temperature, then heating it to 750℃ at a heating rate of 5℃ / min and holding it at that temperature for 360min, then heating it to 1000℃ at a heating rate of 5℃ / min and holding it at that temperature for 120min, and then cooling it in the furnace.

[0045] Example 3

[0046] This embodiment provides a solution treatment method for additive manufacturing of GH3625 alloy, including the following steps: loading the additive manufacturing GH3625 alloy sample into a furnace at room temperature, then heating it to 700℃ at a heating rate of 5℃ / min and holding it at that temperature for 240min, then heating it to 980℃ at a heating rate of 5℃ / min and holding it at that temperature for 60min, and then cooling it in the furnace.

[0047] Example 4

[0048] This embodiment provides a solution treatment method for additive manufacturing of GH3625 alloy, including the following steps: loading the additive manufacturing GH3625 alloy sample into a furnace at room temperature, then heating it to 700℃ at a heating rate of 5℃ / min and holding it at that temperature for 300min, then heating it to 980℃ at a heating rate of 5℃ / min and holding it at that temperature for 120min, and then cooling it in the furnace.

[0049] Example 5

[0050] This embodiment provides a solution treatment method for additive manufacturing of GH3625 alloy, including the following steps: loading the additive manufacturing GH3625 alloy sample into a furnace at room temperature, then heating it to 650°C at a heating rate of 5°C / min and holding it at that temperature for 360 min, then heating it to 950°C at a heating rate of 5°C / min and holding it at that temperature for 60 min, and then cooling it in the furnace.

[0051] Example 6

[0052] This embodiment provides a solution treatment method for additive manufacturing of GH3625 alloy, including the following steps: loading the additive manufacturing GH3625 alloy sample into a furnace at room temperature, then heating it to 650℃ at a heating rate of 5℃ / min and holding it at that temperature for 240min, then heating it to 950℃ at a heating rate of 5℃ / min and holding it at that temperature for 120min, and then cooling it in the furnace.

[0053] Comparative Example 1

[0054] Comparative Example 1 provides a solution treatment method for additive manufacturing of GH3625 alloy, comprising the following steps: loading the additive manufacturing GH3625 alloy sample into a furnace at room temperature, then heating it to 1100℃ at a heating rate of 5℃ / min and holding it at that temperature for 60min, and then cooling it with argon gas.

[0055] Comparative Example 2

[0056] Comparative Example 2 provides a solution treatment method for additive manufacturing of GH3625 alloy, comprising the following steps: loading the additive manufacturing GH3625 alloy sample into a furnace at room temperature, then heating it to 750℃ at a heating rate of 5℃ / min and holding it at that temperature for 360 min, then heating it to 1100℃ at a heating rate of 5℃ / min and holding it at that temperature for 60 min, and then cooling it with argon gas.

[0057] Comparative Example 3

[0058] Comparative Example 3 provides a solution treatment method for additive manufacturing of GH3625 alloy, comprising the following steps: loading the additive manufacturing GH3625 alloy sample into a furnace at room temperature, then heating it to 1100℃ at a heating rate of 5℃ / min and holding it at that temperature for 60min, and then cooling it in the furnace.

[0059] Comparative Example 4

[0060] Comparative Example 4 provides a solution treatment method for additive manufacturing of GH3625 alloy, comprising the following steps: loading the additive manufacturing GH3625 alloy sample into a furnace at room temperature, then heating it to 750℃ at a heating rate of 5℃ / min and holding it at that temperature for 360min, then heating it to 1100℃ at a heating rate of 5℃ / min and holding it at that temperature for 60min, and then cooling it in the furnace.

[0061] Comparative Example 5

[0062] Comparative Example 5 provides a solution treatment method for additive manufacturing of GH3625 alloy, comprising the following steps: loading the additive manufacturing GH3625 alloy sample into a furnace at room temperature, then heating it to 750℃ at a heating rate of 5℃ / min and holding it at that temperature for 360 min, then heating it to 1050℃ at a heating rate of 5℃ / min and holding it at that temperature for 60 min, and then cooling it with argon gas.

[0063] Experimental Example

[0064] To compare and illustrate the deformation and cracking problems of solution treatment in different embodiments and comparative examples, GH3625 alloy parts after solution treatment in different embodiments and comparative examples were compared. The test results are shown in Table 1. Insulation at the low temperature step and slow cooling rate both help to control the deformation of the parts.

[0065] Table 1. Deformation and cracking after solution treatment in different embodiments and comparative examples.

[0066]

[0067]

[0068] The room temperature tensile properties of the alloy samples after solution treatment in different embodiments and comparative examples of the present invention were tested according to GB / T 228.1. The test results are shown in Table 2. The room temperature tensile strength of the embodiments was significantly higher than that of the comparative examples, and the plasticity was only slightly lower than that of the comparative examples.

[0069] Table 2. Room temperature tensile properties test results after solution treatment in different embodiments and comparative examples.

[0070]

[0071]

[0072] The test results above show that the solution treatment of the present invention not only significantly reduces the risk of deformation and cracking of alloy parts, making the products meet strict dimensional requirements, but also significantly improves the tensile strength of alloy parts. At the same time, the reduction in plasticity is controlled within a small range, and the overall mechanical properties are significantly improved.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A solution treatment method for additive manufacturing of GH3625 alloy, characterized in that, Includes the following steps: The additively manufactured GH3625 alloy parts are held at 650-750℃ for 240-360 minutes, then heated to 950-980℃ and held for 60-120 minutes, and then cooled in the furnace. The temperature is increased from room temperature to 650-750℃ at a heating rate of 5℃ / min; during the heat treatment of heating to 950-1050℃, the heating rate is 5℃ / min. The additively manufactured GH3625 alloy part has a thin-walled structure with a wall thickness of 0.5 to 1.0 mm.

2. The solution treatment method according to claim 1, characterized in that, In the solution treatment, the additively manufactured GH3625 alloy part is loaded into the furnace at room temperature.

3. The solution treatment method according to claim 1, characterized in that, The additively manufactured GH3625 alloy part after solution treatment satisfies the following requirements: Room temperature tensile properties of GH3625 alloy parts printed laterally and longitudinally: tensile strength Rm≥830MPa, yield strength Rp 0.2 ≥410MPa, elongation A≥30%.

4. The solution treatment method according to claim 1, characterized in that, The preparation of the additive manufacturing GH3625 alloy part includes: 3D printing GH3625 alloy powder under vacuum or protective atmosphere; the 3D printing power is 220-340W, and the 3D printing scanning speed is 800-1100mm / s.

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